PrevizRender _{(formerly Render Mapper Pro)}

A standalone desktop app that maps videos onto 3D‑scene materials and renders them headlessly — built for LED‑wall / screen‑content workflows where one scene drives many video surfaces.

PrevizRender is one of three sibling tools built by hamLT and powered by Toy Robot Media: Preshow.link plans and previzes the show, UV Studio maps artwork onto the venue's screens, and PrevizRender renders the comps locally. Product site: render.preshow.link (deployed from site/ via GitHub Pages, same as UV Studio's). (Installer and bundle artifacts keep the RenderMapperPro name so auto-updates and install paths stay valid.)

It supports two render backends, chosen automatically by scene type: Blender (.blend, .fbx, .usd, …) and Cinema 4D + Redshift (.c4d). It runs the renderer in the background, so a renderer crash can never take down the app, and ships bundled static ffmpeg/ffprobe so audio muxing and clip probing work out of the box.

Download

Grab the latest from the Releases page. The installer is the easy path; the portable zip is a no‑install folder you can run from anywhere.

Platform	Installer (recommended)	Portable
Windows (x64)	RenderMapperPro-Windows-x64-Setup.exe	RenderMapperPro-Windows-x64.zip
macOS (Apple Silicon)	RenderMapperPro-macOS-arm64.dmg	RenderMapperPro-macOS-arm64.zip

• Windows: run Setup.exe — it installs to Program Files with a Start‑Menu shortcut. If SmartScreen warns, More info → Run anyway (the build isn't code‑signed).
• macOS: open the .dmg and drag the app to Applications. The app is Developer‑ID signed and notarized by Apple — it opens normally, no Gatekeeper warnings.
• Updates are automatic: on launch the app checks Releases and, with one click, downloads and runs the right installer for you — no manual replace.

Nothing else to install. The app is self-contained: ffmpeg is bundled, the .glb web renderer fetches its own headless Chromium on first use, and if Blender isn't already on the machine the app offers to download a managed Blender runtime for you (one click, with a progress bar). The only "bring your own" is Cinema 4D + Redshift for .c4d scenes — that's licensed commercial software, so you point the app at your own install.

Every push to main also publishes the builds as downloadable workflow artifacts under the GitHub Actions run.

Documentation

The full User Guide covers everything with close-up screenshots — quick start, the Watch & Auto-render pipeline, the filename pattern reference, queue, engines, and troubleshooting. The same guide ships inside the app under Help → User Guide.

Quick start

1. Add a scene — drag a .blend / .c4d / .glb (or .fbx, .usd, …) onto the Scene box, then click Scan Scene.
2. Add clips — drag your videos into the Videos list and pick a Camera.
3. Link them — click Auto‑map to match clips to materials by name, or link a selected pair by hand.
4. Set the output — it auto‑fills next to each clip; adjust resolution, frame range and format.
5. Queue & render — hit Queue, then Start (⌘/Ctrl+R), and watch the live preview — or send it to a farm.

New to the app? The in‑app Help → Quick Start is a click‑through version of this with links straight to the relevant settings.

What it does

Map & render

• Load a 3D scene — Blender (.blend, .fbx, .obj, .glb, .usd, .abc, …) or Cinema 4D (.c4d) — plus one or many videos.
• Scan the scene to populate materials and cameras, pulling its own render settings (fps, frame range, resolution, engine, samples, and for C4D the Redshift sampling) straight into the UI.
• Map videos onto materials (full‑bright emission or base‑color/alpha); multiple video→material pairs render in a single pass, at full quality (cubic sampling, texture‑size limits off, no mip down‑scaling).
• Renderer‑aware settings — the panel adapts to the active engine so every control is real:
  • Blender: Cycles/EEVEE, samples, denoise, device, colour transform/exposure/gamma, transparent.
  • Redshift: Speed Preset (Draft→Final), Max/Min samples, adaptive Noise Threshold, denoise, GI bounces / on‑off, Max Ray Depth.
• Output profiles: H.264 MP4, ProRes MOV, PNG/EXR sequence — movie outputs are Rec.709‑tagged (+faststart) so they look identical everywhere.
• Per‑clip audio (speaker badge to mute/include) and an optional burn‑in overlay stamping clip/version/frame/camera/date onto every frame.

Automate the busywork

• Auto‑map by name — clips link to materials when the material name appears in the filename (on import or on demand); gap‑fill only, never clobbers a manual link.
• Watch folder — drop clips into a folder and they import + map themselves. Version‑aware (Screen_v1/v2/_3 → latest wins), auto‑updating the project; half‑copied files are skipped until complete.
• Auto‑render targets — mark the screens a render must cover; once the watch folder fills every target (or a newer version lands) a single multi‑screen render queues automatically with a PREVIZ suffix. Queue‑only or auto‑start.
• Asset grouping → previz auto‑export — for shows on a structured naming convention (e.g. PRJ001_D01_S01_A017_CENTER_ANIM_V003), the watch folder groups dropped clips by setup + asset, maps each screen code to its material, keeps the newest version, and exports one multi‑screen previz render per asset — drop 10 clips, get 5 assets. The parser (regex), content‑type filter, output‑name tokens, screen→material overrides and per‑setup scene routing are all configurable in Properties → Watch & Auto‑render → Asset grouping. A newer version updates that asset's job in place rather than piling up.
• Auto‑retry a failed job once, and an aspect guard that warns when footage doesn't match its screen (16:9 clip on a 21:9 wall).
• Delivery copy — finished renders can copy themselves into a review/delivery folder.
• Automatic updates — the app checks Releases on launch and one‑click downloads + runs the right installer. The repo is public, so this uses the anonymous GitHub API — no credential is baked into the build.

Scale to a farm

• Thinkbox Deadline — submit Blender and Cinema 4D jobs. C4D jobs are baked and rendered with the licensed Cinema 4D command‑line renderer; jobs carry the app icon in the Deadline Monitor and spread frames across nodes. Auto‑chunking sizes frames‑per‑task from render history; Deadline → Farm Nodes… lists the farm; right‑click a job to Set Priority or Requeue.

Review & track

• Analytics & cost — every render records seconds/frame, total time and estimated power cost (set wattage + rate in Tools → Power & Cost), shown live and in Tools → Render History, with an upfront ETA from prior runs.
• Output review — auto‑generated contact sheets per render and a shareable HTML report with timing, cost and embedded thumbnails.
• Notifications — pinged on complete/fail via the system tray and/or a Discord webhook; everything also logs to Live Logs.
• Command palette (⌘/Ctrl+K) to run any action by name, plus a light/dark theme toggle.

Live Preview

• Pick any frame with the frame scrubber (prev/next, slider, frame field) and render just that frame — fast, at a chosen render scale (Full / ½ / ¼ / ⅛).
• Auto mode re‑renders the preview whenever you change the camera, resolution, frame, mapping, etc. (debounced, and coalesced so updates never pile up).
• Display zoom like After Effects: double‑click toggles Fit ⇄ 100%, centred on the clicked pixel; grab to pan at 100%. The image scales to the panel in Fit.
• Shows render time and pixel size; the finished movie plays (looped) in the same pane after a full render.

Queue

• Auto‑draft: the moment you map a video it becomes a live job; edits save into it continuously — no "unsaved changes" limbo, no save dialog.
• Always exactly one active job (remembered across sessions); selecting a row opens it, switching never loses work.
• Double‑click a job name to rename (sticks; auto‑labels are tagged with the camera otherwise).
• New jobs are added at the top; ⌘/Ctrl+D duplicates, Delete removes, right‑click for Duplicate / Set Priority / Requeue / Reveal / Open / Move / Clear Queue.
• Per‑row Run checkbox and progress; live, filterable logs (text + level filters).

Project / preset files

• Projects — .rmproj (full setup: scene, clips, mappings, queue).
• Presets — .rmpreset (reusable render‑settings recipe).

Both are JSON under the hood. App data lives in ~/.blender_video_mapper/: profile.json (auto‑saved state), presets/*.rmpreset, logs/app_qt.log, reports/.

Project structure

• app_qt.py — the Qt (PySide6) desktop UI.
• theme.py / icons.py — dark theme tokens + SVG icon set that drive all styling.
• blender_worker.py / blender_discover.py — headless Blender render + scene discovery.
• c4d_worker.py / c4d_discover.py — headless Cinema 4D + Redshift render/bake + discovery (run under c4dpy).
• deadline/RenderMapperPro/ — custom Deadline plugin (app icon + cross‑platform C4D Commandline render); installed into the repository's custom/plugins/.
• core/ — UI‑agnostic logic: models.py (job config), runner.py (subprocess + Deadline submission), discovery.py, utils.py (output paths, name auto‑match, version reconciliation).
• tests/ — pytest suite for core/ (matching, versioning, runner, Deadline submission).
• BlenderVideoMapper.spec — PyInstaller build spec (bundles both workers + ffmpeg).

Run from source

Requires Python 3.12 and Blender installed.

python -m pip install -r requirements-build.txt   # PySide6 + PyInstaller
python tools/fetch_ffmpeg.py                       # vendored ffmpeg/ffprobe
python app_qt.py

Then set the Blender executable in Properties (e.g. /Applications/Blender.app/Contents/MacOS/Blender), pick a scene, Scan, add videos, map them, and use Preview Frame / the queue.

Build a standalone app

python -m pip install -r requirements-build.txt
python tools/fetch_ffmpeg.py
python -m PyInstaller --noconfirm --clean BlenderVideoMapper.spec
# → dist/Render Mapper Pro.app  (macOS)  /  dist/Render Mapper Pro/  (Windows)

GitHub Actions (.github/workflows/build.yml) does this for macOS (Apple Silicon) + Windows on every push to main. The Windows job also compiles a Setup.exe with Inno Setup and the macOS job builds a .dmg (see installer/); pushing a v* tag publishes a Release with both the installers and the portable zips. (macOS is Apple-Silicon-only — the deprecated Intel runner build was dropped; a universal2 build is the path back to Intel support if needed.)

Development

pip install pytest ruff
pytest -q                                           # unit tests
ruff check core tests blender_worker.py blender_discover.py

CI runs the same lint + tests as a gate before the build matrix.

Blender notes

• The worker creates/updates AUTO_VIDEO_TEXTURE nodes per mapped material; emission mode wires the clip to an emission shader so screens stay fully visible.
• Video clips map over the full timeline; the single‑frame preview renders one scene frame while keeping that timeline in sync.
• Timeout / idle‑timeout controls can terminate stalled runs; safe mode validates paths/extensions in the worker.

Cinema 4D + Redshift notes

• Requires Cinema 4D 2026 (auto‑detected via c4dpy) with Redshift; the clip is injected into the target material's Redshift emission as a full‑bright image sequence (Redshift can't read .mp4, so frames are extracted with the bundled ffmpeg).
• Local renders/preview run under c4dpy. Farm renders bake a self‑contained .c4d (relative sequence paths) and render it with the licensed Cinema 4D Commandline — so any node that already renders C4D works, with no extra licensing setup.
• Farm prerequisites: each render node needs Cinema 4D + Redshift licensed (as for the stock Cinema4D plugin). The RenderMapperPro Deadline plugin lives in deadline/RenderMapperPro/ and is installed into the repository's custom/plugins/.